Understanding Nmap analysis techniques

SCANNER

How does the popular Nmap scanner identify holes in network security? In this article, we examine some Nmap analysis techniques.

Network scanning is nearly as old as the network. In former times, hackers used modems to test blocks of phone numbers and record responses in a process known as wardialing. Today, port scanners transmit specially crafted IP packets across the Internet to discover and identify live systems. Nmap (the Network Mapper [1]), which was first introduced by Fyodor in September 1997 [2], is probably one of the most comprehensive network scanning tools. Fyodor was unhappy with the features that tools such as Strobe [3] or Pscan [4] offered. He wanted a utility that would out-perform anything seen before – a feat that he certainly achieved with Nmap.

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